@selectors: blue, green, red;

each(@selectors, {
  .sel-@{value} {
    a: b;
  }
});


@set: {
    one: blue;
    two: green;
    three: red;
  }
  .set {
    each(@set, {
      @{key}-@{index}: @value;
    });
  }

  .set-2() {
    one: blue;
    two: green;
    three: red;
  }
  .set-2 {
    // Call mixin and iterate each rule
    each(.set-2(), .(@v, @k, @i) {
      @{k}-@{i}: @v;
    });
  }

  each(range(4), {
    .col-@{value} {
      height: (@value * 50px);
    }
  });